特厚煤层超前采动原位应力演化规律研究

特厚煤层超前采动应力演化规律是顶板控制的基础,但目前缺乏现场采动过程应力演化的研究成果。依托同煤集团同忻矿8309工作面,进行了特厚煤层采动应力演化规律原位实测研究。现场试验结果表明:随着工作面推进,前方煤岩扰动强度不断增大,支承压力由原岩应力逐渐上升至峰值强度,然后随着煤岩的破坏开始下降至残余强度;侧向水平应力则呈现出阶段性稳态降低的趋势。根据支撑压力规律,工作面前方煤岩具有扰动分区化特征:该试验点工作面前方200 m以上为未扰动区域;工作面前方100~200 m为弱扰动区域;工作面前方50~100 m为强扰动区域;工作面前方50 m以内为剧烈扰动区域,结合工作面前方不同区域扰动强度提出了针对性的分区支护措施建议。研究成果可为室内开展扰动应力路径加卸载试验和特厚煤层现场安全高效开采提供指导。

Study on in-situ stress evolution law of ultra-thick coal seam in advance mining

The law of stress evolution in advance mining is the basis of roof control in super thick coal seam,but the research results of stress evolution in field mining process are lack at present.Based on the No.8309 working face of Tongxin Mine in Tongmei Group,the insitu measurement of the evolution rule of mining stress in extra thick coal seam is carried out.The field test results show that: with the advance of the working face,the disturbance intensity of coal and rock in front increases,the bearing pressure gradually rises from the original rock stress to the peak strength,and then decreases to the residual strength with the destruction of coal and rock;the lateral horizontal stress shows a steady-state decreasing trend in stages.According to the law of support pressure,the coal and rock in front of the mining face have the characteristics of disturbance zoning: the area 200 m in front of the working face of the experimental point is undisturbed;the area 100 ~ 200 m in front of the working face is weak disturbance;the area 50 ~ 100 m in front of the working face is strong disturbance;the area 50 m in front of the working face is violent disturbance.Combined with the disturbance intensity of different areas in front of the working face,targeted zoning support measures are proposed advise.The research results can provide guidance for the laboratory test of disturbance stress path and also for the safe-efficient mining of extra thick coal seam.